SeamRemote and @WebRemote

Think of the scenario that you develop a Seam based application and you want to do some AJAX calls / requests to your bean but you don’t want to use the Richfaces/A4J based AJAX functionality (maybe because you have some large forms and don’t want to post the complete form data). In such a case you can use SeamRemoting. There are some steps to perform before you can use SeamRemoting.

Make sure that the jboss-seam-remoting.jar is in your classpath.
Add

        <servlet>
            <servlet-name>Seam Resource Servlet</servlet-name>
            <servlet-class>org.jboss.seam.servlet.SeamResourceServlet</servlet-class>
        </servlet>
        <servlet-mapping>
            <servlet-name>Seam Resource Servlet</servlet-name>
            <url-pattern>/seam/resource/*</url-pattern>
        </servlet-mapping>

to your web.xml. After that you can create a backing bean, eg something like this:

import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.remoting.WebRemote;

import com.hp.ci.web.persis.action.BaseAction;
import com.hp.ci.web.persis.common.exception.BusinessException;

@Name("remoteTestClass")
public class RemoteTestClass extends BaseAction{
    @WebRemote
    public String testMethod() {
        String[] array = {"Hello world", "Foobar.com", "John Doe was here", "Another random string"};
        int randomIndex = (int)(Math.random() * array.length);
        return array[randomIndex];
    }
}

You simply expose the method via the @WebRemote annotation. To use this method now in your UI (e.g., a JSF site), you can include something like this:

<!DOCTYPE composition PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
                             "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<ui:composition xmlns="http://www.w3.org/1999/xhtml"
                xmlns:s="http://jboss.com/products/seam/taglib"
                xmlns:ui="http://java.sun.com/jsf/facelets"
                xmlns:f="http://java.sun.com/jsf/core"
                xmlns:h="http://java.sun.com/jsf/html"
                xmlns:rich="http://richfaces.org/rich"
                xmlns:a4j="http://richfaces.org/a4j">

<ui:define name="errmessage">
   <rich:messages  globalOnly="true" errorClass="messageError" 
         fatalClass="messageFatal" infoClass="messageInfo" warnClass="messageWarn"/>
</ui:define>
...    
        <p/>
        <h:panelGrid>
            <h:panelGroup>
                <h:outputText value="AJAX / Seam Remoting test"/>
                <p/>
                <s:remote include="remoteTestClass"/>
                <a href="Javascript:callMe()">Invoke ajax method</a>
                <s:div id="testDIV">

                </s:div>
                <script type="text/javascript">
                    //<![CDATA[
                        function callMe() {
                            Seam.Component.getInstance("remoteTestClass").testMethod(myCallBackM);
                        }

                        function myCallBackM(result) {
                            document.getElementById("testDIV").innerHTML=result;
                        };
                    //]]>
            <script>
                <hr/>
            </h:panelGroup>

        <h:panelGrid>
...
</ui:composition>

The <s:remote …> tag includes the needed Javascript files. Instead of this you can include the Javascript files in this way:

<script type="text/javascript" src="/TestApp/seam/resource/remoting/resource/remote.js"> </script>
<script type="text/javascript" src="/TestApp/seam/resource/remoting/interface.js?remoteTestClass">

To use more than one ‘remote class/backing bean’ method use the ‘request parameter notation’, e.g.: v